class Animal {
  constructor(name, month) {
    this.name = name;
    this.month = month;
  }

  eat() {
    console.log(`${this.name} is eating`);
  }
}

class Rabbit extends Animal {
  constructor(name, month, type) {
    super(name,month);
    this.type = type;
  }
  jump() {
    console.log(this);
  }
}

let rabiit = new Rabbit("小白兔", 12, "野兔");
rabiit.eat();
rabiit.jump();
